Which statement about the Output Latch (OTL) is true?

• A. It can both set and reset the output
• B. It can turn on and latch, but cannot turn off
• C. It only affects counters
• D. It is used to reset inputs

Answer: (B)

Output Latch is all about creating a memory-like on state for an output. When the rung with the latch becomes true, the coil is energized and the output goes on. That on state is stored, so the output stays energized even if the input condition that triggered the latch goes back to false. It will only turn off when another instruction explicitly resets it—typically an Output Unlatch (OTU) or a reset condition on a separate rung. So the statement that describes the Output Latch as turning on and then latching, but not turning off by itself, matches how this function behaves. It isn’t used to control counters, and it isn’t used to reset inputs; its purpose is to maintain an output in the on state until a reset is issued.